[Bug]: Prism isn't correctly used as the default for streaming pipelines.

[robertwb]

What happened?

There are errors in both the fallback code and unbounded PCollections are not detected.

This was noted particularly when attempting to use Kafka from Python which tries to use the batch runner (and also can't use the bundle based runner due to cross-language).

Issue Priority

Priority: 1 (data loss / total loss of function)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Infrastructure
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner

[Abacn]

This Issue is marked as Beam 3 - Milestone 1: No Code and ML focus. Please help us burning down the open blocker tasks.

• If this issue is solved, close it. If it is obsolete, close as not planned. If it is no longer necessary for Beam 3, move it out of the Milestone.

• If the work is pending, please be reminded that Milestone 1 is targeted for completion by Dec 30, 2025

• If this issue involves multiple milestones (e.g. remove a public API should first mark it as deprecated, scoped in Milestone 1; then finally remove it in Beam 3 release candidate, scoped in Milestone 3) and Milestone 1 portion has completed, consider move the Issue to Milestone 3.

[damccorm]

This has been fixed as part of making prism the default.